This invention relates generally to the field of negative-type photosensitive resin compositions. In particular, this invention relates to photosensitive resin compositions containing an epoxy compound and to a method for the formation of a resist pattern using resin composition.
Currently, an epoxy resin composition containing epoxy resin and phenol resin is commonly used as a sealing material for semiconductor devices, such as IC, LSI, due to the high reliability of the material.
In order to achieve better physical properties, recently, a photosensitive resin composition containing phenol resin as well as an epoxy compound has been proposed as a photoresist in the manufacturing process of wafer-level-chip-size package (WL-CSP). However, this type of photosensitive resin composition has a low solubility in the developing agents commonly used in the industry, such as an aqueous solution of tetramethylammonium hydroxide (abbreviated herein as TMAH), causing difficulties in the developing step. Therefore, it is highly desirable to develop a new photosensitive resin material, which is able to retain the excellent physical properties of the epoxy resin, such as high-temperature impact resistance, but without having the problem mentioned above.